Flange assembly with improved serviceability

ABSTRACT

The invention is directed at joint assembly which includes a first part and a second part to be assembled together. The first and second part are secured together via a set of fasteners and a set of attachment portions. The set of attachment portions cooperate with one of the first or second parts and receive the set of fasteners.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application based on U.S. patentapplication Ser. No. 12/936,279, which is the United States nationalphase of international application No. PCT/CA09/00439 filed Apr. 6,2009, which claims the benefit of priority of U.S. provisional patentapplication No. 61/042,364 filed Apr. 4, 2008, and U.S. provisionalpatent application No. 61/051,730 filed May 9, 2008, which areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention is directed generally at joint assemblies. Morespecifically, the present invention is directed at a joint, or flange,assembly with improved serviceability.

BACKGROUND OF THE INVENTION

Joint and flange assemblies are used in many different technologicalfields and suffer from various disadvantages and problems. For example,with exhaust flanges that are used in the automotive industry, costs areincreasingly becoming a critical factor in the manufacture of car partsand many companies are trying to reduce their costs by reducing theirlabor or material expenses. Another problem that manufacturers face isthat their exhaust systems are required to meet emission standards overa predetermined period of time. As a result, individual parts within theexhaust system, such as exhaust flanges, must be fully operationalduring a warranty period, which can be a very difficult task.

Another problem faced by manufacturers of exhaust flanges is damage dueto corrosion. Currently, exhaust flanges are manufactured entirely usingstandard carbon steel or stainless steel, but both of these materialshave inherent disadvantages. Stainless steel exhaust flanges haveadequate corrosion resistance but are costly to produce and therefore,the cost of replacing stainless steel exhaust flanges is relativelyhigh. On the other hand, carbon steel exhaust flanges are cost-effectivebut typically corrode quickly and, as a result, are difficult to servicewithin the warranty period.

It is therefore desirable to provide a novel joint assembly whichovercomes at least one of the disadvantages of prior art jointassemblies.

SUMMARY OF THE INVENTION

It is an object of the present invention to obviate or mitigate at leastone disadvantage of previous joint or flange assemblies.

In a broad aspect, there is provided a flange assembly comprising: afirst flange portion having an interface for receiving a first end of apipe; a second flange portion having an interface for receiving a secondpipe; a set of fasteners extending through the first and second flangeportions; and a set of attachment portions cooperating with one of thefirst or second flange portions for receiving the set of fasteners tosecure the first and second flange portions together.

In another broad aspect, there is provided a joint assembly comprising:a first part; a second part; a set of fasteners; and a set of attachmentportions cooperating with one of the first or second parts for receivingthe set of fasteners to secure the first and second flange portionstogether.

In yet another broad aspect, there is provided an attachment portion foruse with an assembly including at least one flange portion, theattachment portion comprising: an abutment portion; and an engagementportion, connected to the abutment portion, for cooperating with the atleast one flange portion and for receiving a fastener for securing theassembly; wherein the attachment portion can be easily knocked out fromthe at least one flange portion when required.

Other aspects and features of the present invention will become apparentto those ordinarily skilled in the art upon review of the followingdescription of specific embodiments of the invention in conjunction withthe accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate several embodiments of theinvention, as examples only. Other variations will be apparent to thoseknowledgeable in the field of the invention.

FIG. 1 a is a perspective view of an embodiment of a flange assembly;

FIG. 1 b is an axonometric projection of an embodiment of an attachmentportion;

FIG. 1 c is an axonometric projection of a further embodiment of anattachment portion with splines;

FIG. 1 d is an axonometric projection of an embodiment of an attachmentportion in which the engagement portion includes an eccentric portionfor preventing rotation of the attachment portion;

FIG. 1 e is a cross section of another embodiment of an attachmentportion in which the engagement portion does not extend into a flangebody;

FIG. 2 a is a cross section of an embodiment of a flange assembly inwhich the set of attachment portions and the set of holes havecorrespondingly tapered surfaces;

FIG. 2 b is a cross section of a further embodiment of a flange assemblyin which the attachment portions extend through the first flange bodyand into the second flange body;

FIGS. 3 a to 3 d show embodiments in which one or more notches areprovided for prying an attachment portion away from the first flangebody;

FIG. 4 is a cross section of an embodiment of a flange assembly furthercomprising a corrosion-resistant shield;

FIG. 5 a is a cross-sectional view of an embodiment of a flange assemblyin which the first portion has a protrusion for engaging a recessedportion in the second portion;

FIG. 5 b is a cross-sectional view of a further embodiment of a flangeassembly in which the first portion has a protrusion, with an augmentedinterference rib, for engaging a recessed portion in the second portion;

FIG. 5 c is a view of the embodiment shown in FIG. 5 b taken along line5 c;

FIG. 5 d is an axonometric projection of an attachment portion with atapered engagement portion;

FIG. 6 a is a schematic diagram showing the first step in a method forpre-assembling gaskets;

FIG. 6 b is a schematic diagram showing a second step corresponding toFIG. 6 a;

FIG. 6 c is a perspective view showing the positioning of the gasket forinstallation according to FIGS. 6 a and 6 b;

FIGS. 7 a to 7 d are a series of diagrams showing a flange assembly witha shield that engages a sloped edge of the second flange portion; and

FIG. 8 is a perspective view of an attachment portion with a partialshield.

DETAILED DESCRIPTION

Generally, the present invention provides a joint, or flange, assemblyincluding an attachment portion that provides improved serviceability,and in some embodiments, improved corrosion resistance.

As will be understood, the described flange assembly can be used in anyenvironment in which flange assemblies are required, such as thepetrochemical industry, water treatment industry, and particularly, inthe automobile industry for exhaust flanges. When used in an automobile,the flange assembly and attachment portion, and similar embodiments, canbe used at any flange joint where improved serviceability would bebeneficial

Turning to FIG. 1 a, a perspective view of an embodiment of a flangeassembly 10 is shown. The flange assembly 10, or exhaust flange,includes a first portion 12, a second portion 22, a set of attachmentportions, or knock outs, 18, and a set of fasteners, such as bolts, 26.The first portion 12 has a first, or first portion, flange body 14,which provides an interface for connecting to a first pipe 16, whichmay, for example, extend toward the direction of an engine (not shown).The first flange body 14 also has a first set of holes 15 for engagingthe set of attachment portions 18.

The second portion 20 has a second, or second portion, flange body 22,which provides an interface for connecting to a second pipe 24. Thesecond flange body 22 includes a set of holes 25 that corresponds to theset of holes 15 and attachment portions 18. When the first portion 12and the second portion 22 are mated, the set of fasteners 26 is insertedthrough the sets of holes 25 and 15, and engaged by respective ones ofthe set of attachment portions 18. Although not shown in FIG. 1, agasket can be placed between the first 12 and second 20 portions toprovide a tighter seal between the two surfaces, as described below withrespect to FIGS. 2, 5, 7 a, and 7 b. It will be understood that in analternative embodiment, the attachment portions 18 can engage the secondflange body 22 while the fasteners extend from the first portion 12.

As shown in FIG. 1 b, which is a perspective view of a first embodimentof an attachment portion, the attachment portion 18 has an engagementportion 9 which engages a respective hole, or recessed portion, 15 inthe first flange body 14, an abutting, or abutment, portion 8 whichabuts the first flange body 14, and a bore 7 which engages a respectivefastener 26. In the preferred embodiment, the engagement portion 9 isconnected axially to the abutment portion 8. In one embodiment, the bore7 does not extend fully through the abutting portion, protecting theengaged fastener 26 from debris, and the attachment portions 18 can besecured to the first flange body 14 so that they do not become dislodgedduring transport of the first portion 12. A flat portion of engagementportion 9 restricts, or prevents the attachment portion 18 fromrotating, or reduces the amount or rotation, within hole 15.Furthermore, the attachment portions 18 can also be secured to the firstflange body 14 in a manner such that when the second portion 20 is to bedisassembled from the first portion 12, the attachment portions 18 canbe easily knocked out or pried away from the first flange body 14.Removal of the attachment portions 18 allows for new components, such asa new second portion 20, to be relatively easily installed whennecessary. As will be understood, new attachment portions 18 arerequired to be assembled within the first flange body 14 before the newsecond portion 20 is installed. In an alternative embodiment, the bore 7extends fully through both the engagement portion 9 and the abuttingportion 8 such as shown in FIG. 2 b.

In a further embodiment shown in FIG. 1 c, the attachment portion 18 canbe secured to the first flange body 14 by providing splines 19 orknurling on the engagement portion of each of the set of attachmentportions 18.

In yet another embodiment, FIG. 1 d shows an attachment portion 18 inwhich the engagement portion 9 comprises a concentric portion 6 that isconcentric relative to the bore 7, and an eccentric portion 4 that iseccentric relative to the bore 7. The attachment portion 18 is intendedto cooperate with the first flange body that is correspondingly shapedto receive the engagement portion 9. The eccentric portion 6 preventsrotation of the attachment portion 18 about the axis of bore 7.

In another embodiment, FIG. 1 e shows an attachment portion 18 having anengagement portion 9 that defines a circular recess. In this embodiment,the bore 7 extends at least partially through the abutment portion 8,but not through the engagement portion 9. The circular recess engages acorrespondingly raised portion 13 of first flange body 14, creating apressed fit that prevents unintentional dislodgement or rotation of theattachment portion 18. However, the attachment portion 18 can be easilyknocked out or pried away from first flange body 14 for improvedserviceability.

FIG. 2 a show a cross section of another embodiment of a flange assembly10 with first 12 and second 20 portions in a mated position. In thisembodiment, the first flange body 14 and the second flange body 22 canbe manufactured from a material such as carbon steel. As shown, thefirst portion 12 is mated to the second portion 20 with a gasket 38between the first 14 and second 22 flange bodies, and the first 12 andsecond 20 portions locked in place by the set of fasteners 26 engagingwith the set of attachment portions 18. In this embodiment, each one ofthe set of attachment portions 18 includes a tapered engagement portion30, and each one of the set of holes 15 is correspondingly tapered sothat the set of attachment portions 18 cooperate with or can be securedto the first flange body 14 when the two are pressed together. In afurther embodiment, the set of attachment portions 18 can be secured tothe first flange body 14 by providing splines or knurling 19 on theengagement portion of each of the set of attachment portions 18.

FIG. 2 b shows a cross-section of another embodiment of a flangeassembly 10 with first 12 and second 20 portions in a mated position. Inthis embodiment the engagement portions 9 of the attachment portions 18are greater than the width of the first portion 12, and extend throughthe first portion 12 and into second portion 20, which iscorrespondingly recessed to receive the engagement portions 9. Theengagement portions 9 hold a gasket 38 in place and serve as a barrierto external elements, providing protection to the flange assembly fromcorrosion causing debris. Additionally, the engagement portions 9provide flange assembly 10 with an additional source of load-bearingability. The cooperation of the engagement portions 9 with the secondportion 20 supports the joint against sheering and bending, whichincreases the strength of the flange assembly 10 without using moreresilient, and typically more costly, materials. Moreover, less of thefasteners 26 is exposed and unsecured when the fasteners 26 are securedin the attachment portions 18, and the fasteners 26 are therefore lesssusceptible to the high heat and stretch that is typically experiencedby a flange assembly, especially in an automotive environment. Thismakes it possible to select materials for the fasteners 26 that havemore conventional stretch under high heat conditions. In most knownflange assemblies, there is no attachment portion 18 and therefore theend of the fastener 26 is exposed after the edge of the first flangebody. This can lead to a higher rate of wear and tear, or damage, to thefastener 26 under operating conditions.

Turning to FIGS. 3 a to 3 d, several embodiments are shown in which anattachment portion 18 is engaging a hole in the first flange body 14.FIG. 3 a shows a cross section of an embodiment in which the edge of theflange body 14 includes a notch 32 adjacent the attachment portion 18.In this embodiment, the attachment portion 18 can be disengaged from thefirst flange body 14 and the fasteners 26 by using a tool, such as ascrewdriver, puller or similar tool, as the notch 32 provides a recessedaccess area in which the tool can be inserted. As shown in FIGS. 3 b to3 d, the flange body 14 can include up to three notches, or slots,whereby the tool can be inserted to pry the attachment portion 18 awayfrom the first flange body 14.

Alternatively, the set of attachment portions 18 can also be knocked outof the first flange body 14 using various methods as necessary duringservicing. In one method, the fasteners 26 can be removed, or unscrewed,and the attachment portion 18 knocked out. In another method, the headof the fasteners 26 can be cut away and the stem of the fasteners 26 andthe attachment portion 18 knocked out of the holes. In yet a furthermethod, the attachment portion 18 can be removed by pulling theattachment portion 18 away from the first flange body 14.

Turning to FIG. 4, a cross section of a further embodiment of a flangeassembly 40 is shown. In this embodiment, the flange assembly 40includes a first portion 42 and a second portion 44, the portionsincluding a first 46 and a second 48 flange body, respectively. Thefirst 42 and second 44 portions are held in place by a set of fasteners52 which are locked in place by a set of attachment portions 54. Thesecond flange body 48 is preferably manufactured from a material such ascarbon steel, while the first flange body 46 is also manufactured fromcarbon steel with a corrosion-resistant shield 50 or shell, made ofstainless steel. The shield 50 assists in protecting the flange assembly40 from external conditions, such as the environment or corrosioncausing debris. The shield 50 can be placed over the first flange body46 or can be bonded, secured, or fastened to the first flange body 46. Agasket can be inserted between the two flange bodies in order to providea tighter seal between the surfaces of the flange bodies. It will beunderstood that in alternative embodiments, the shield can be applied tothe second flange body 48.

In an alternative embodiment, rust protection can be applied between theshield and the first flange body 46 to provide further protection fromcorrosion. In yet another embodiment, in order to reduce the amount ofrust-causing debris from entering between the shield 50 and first flangebody 46, one can peen over the edge between the shield 50 and the firstflange body 46 to provide a better seal.

Turning to FIG. 5 a, a cross-section of another embodiment showing themating between a first portion 62 and a second portion 66 is shown. Afirst flange body 60 of the first portion 62 is mated with a secondflange body 64 of the second portion 66 with a gasket 68 locatedtherebetween to provide a tighter seal between the surfaces of the first60 and second 64 flange bodies. An attachment portion 70, having atapered engagement portion 72, is located within a hole in the flangefirst body 60, for receiving a fastener (not shown), which locks thefirst 60 and the second 64 flange bodies in place. The second flangebody 64 includes a recessed portion 76 which receives a protrusion 74extending from the first flange body 60. The protrusion 74 can extend upto the full thickness of the flange joint, and the cooperation of theprotrusion 74 and the recessed portion 76 assists in aligning the first60 and the second 66 portions with respect to each other, acting as aninterference rib for securing the gasket 68 during the assembly of theflange assembly, and holding the gasket 68 in place after assembly.Furthermore, the cooperation of the protrusions 74 with the recessedportions 76 provides the flange assembly with additional load-bearingability by supporting the joint against sheering and bending, whichincreases the strength of the flange assembly without using moreresilient, and typically more costly, materials.

An advantage of this embodiment is that when the protrusions 74 bear theload of the system, the strength requirement for the fastener isreduced. The protrusions 74 also provide protection of the flangeassembly from corrosion causing debris as it serves as a barrier toexternal elements. In a further embodiment, the attachment portion 70can provide further coverage of the fastener past the abutting edge ofthe first flange body 60. In an alternative embodiment, the first flangebody 60 includes a recessed portion for receiving a protrusion thatextends from the second flange body 64.

In an alternative embodiment discussed earlier and shown in FIG. 2 b,instead of the protrusion 74 being part of the first flange body 60, theprotrusion 74 is provided by the attachment portion 70 by extending theengagement portion of the attachment portion 70 into the recessedportion 76 of second flange body 64, including up to the full thicknessof the flange joint.

FIG. 5 b shows a further embodiment in which protrusion 74 has anaugmented interference rib 75 that retains gasket 68 in position by aninterference fit during and after assembly of the flange assembly. FIG.5 c shows a view taken along line 5 c in FIG. 5 b of first flange body60 with lips 75 extending from protrusions 74.

In FIG. 5 d, a further embodiment of an attachment portion 70 is shown.In this embodiment, the attachment portion 70 can include a prevailingtorque feature, which acts as a locking feature. An advantage is that itis more cost effective to place this feature on the attachment portion70 rather than on other parts of the flange assembly, thereby loweringthe cost of the overall flange and/or flange assembly.

Turning to FIG. 6 a-6 c, a method of pre-assembling a gasket isprovided. The gasket 80 is initially placed over a protrusion 82 locatedon a flange body 84, typically the replacement flange body. The gasket80 can then be crimped so that the edge of the gasket 80 is bentslightly downwards so that the gasket is somewhat locked in position.

Turning to FIGS. 7 a to 7 d, partial views of another embodiment areshown. In FIG. 7 a, the flange assembly 90 includes a first flange body92 and a second flange body 94. A gasket 96 is located between the firstflange body 92 and the second flange body 94 to assist in providing atighter seal between the two flange bodies when they are mated together.The first flange body 92 includes a shield 98 which provides addedprotection to the flange assembly 90. The shield 98 is similar to theshield 50 discussed in the description of FIG. 4.

In one embodiment, when manufacturing a flange from a mixture of carbonor stainless steel and hexagonal Boron Nitride (“hBN”), when the flangeis sintered the hBN material rises to the surface away from the carbonor stainless steel to provide the protective outer shield around theflange body such that the shield 98 is made from hBN. The shield 98 orshell, reduces or prevents corrosion by protecting the joint fromcorrosion and/or erosion causing debris. Generally, the hBN materialprovides improved protection over regular carbon or stainless steel.

As shown in FIG. 7 b, when the first flange body 92 is urged towards thesecond flange body 94, the shield 98 contacts a sloped portion 100 ofthe second flange body 94 to create a seal which is held in place whenthe fasteners is fully engaged with the attachment portion.

In some cases, the edge of the shield 98 can be damaged in transit whenit is transported with first flange body 92, as a portion of the shieldhangs over the edge of the first flange body 92. FIGS. 7 c and 7 d showa method for avoiding such damage. FIG. 7C shows this embodiment, inwhich prior to delivery, the shield 98 is placed over the first flangebody 92 with a small gap 102 between the first flange body 92 and theshield 98 and held together with enough friction to remain intact duringshipment but not enough to prevent a fastener from tightening the flangeduring assembly. In this manner, the edge of the shield 98 is alignedwith the edge of the first flange body 92 so that there is less concernor fear that the edge of the shield 98 will be damaged during transit.In this position, an attachment portion 104 can be partially engagedwith a hole in the first flange body 92.

As shown in FIG. 7 d, once the first flange body 92 and the shield aredelivered, a fastener can be tightened in cooperation with theattachment portion 104, tightening the first 92 and second 94 flangebodies with respect to each other and forming a seal between the shield98 and the sloped portion 100 of the second flange body. The sealbetween the first 92 and second 94 flange bodies reduces or preventscorrosion causing debris from entering the joint. Although not shown, agasket can also be located between the first 92 and second 94 flangebodies to provide a tighter seal.

Turning to FIG. 8, a perspective view of an embodiment of an attachmentportion 110 having a partial shield 112 is shown. As with the otherembodiments, the engagement portion 114 of the attachment portion 110 isinserted into a hole in a flange body to receive a fastener which isused to tighten the flange portions together to form a flange assembly.When the attachment portion 110, engages the flange body, the partialshield 112 partially covers the joint portion between the first andsecond flange bodies to protect the flange assembly from possiblecorrosion and erosion. In this embodiment, the partial shield 112 islocated over the area which is most susceptible to corrosion or erosionfor cost effectiveness of the flange assembly. For example, if theattachment portion 110 is used in the embodiment shown in FIG. 5 a, thepartial shield 112 provides a cover for the joint between the first 60and the second 64 flange bodies.

In another embodiment, the flange bodies can be manufactured from powdermetal so that the holes in the flange body can be shaped to anydimension. In this manner, the holes can be shaped to fit any shape orsize of fastener or attachment portion. Furthermore, a protrusion can beany size or shape. Therefore, the geometry of the protrusions and holesmay be selected to vary the load-bearing characteristics of the flangeassembly to meet the to load-bearing requirements for differentconditions. For example, just as an I-beam is designed to take a bendingload, the protrusion geometry can be designed to take the load in thespecific flange application.

In another embodiment, the flange bodies can include means for receivingone or more extra pins, such as pins manufactured from powder metal ordowel pins, to increase the overall sheer strength. This also allowseach of the set of fasteners to be reduced in diameter thereby improvingcost effectiveness for the flange assembly. The pin or pins can be aseparate part or can be integral with one or both flange portions.

In yet another embodiment, when manufacturing the flange from powdermetal, the weight and cost of the flange body can be controlled sincethe load bearing requirements are being handled by other areas or partsof the flange assembly and there is an improved method of focusing theload bearing while providing improved serviceability. This can increasethe weight in those areas but in areas of less loads, the weightstructure of these areas can be adjusted accordingly to reduce weightand cost.

In another embodiment, the features described in the above embodimentsare applied to a manifold flange. Application of the features describedin the above embodiments, including the use of the set of attachmentportions, in a manifold flange, such as (1) stamp or tubular/fabricateflanges or (2) cast manifold flanges, provides improved serviceabilityover conventional manifold flanges. In this embodiment, a set offasteners extend through a first part, or portion, such as a manifoldflange, and a second part, or portion, such as an engine block. A set ofattachment portions engages or cooperates with either the first orsecond part, and receives the set of fasteners to secure the first andsecond parts together.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments of the invention. However, it will be apparent to oneskilled in the art that these specific details are not required in orderto practice the invention. For greater clarity, the above-describedembodiments of the invention are intended to be examples only.Alterations, modifications and variations can be effected to theparticular embodiments by those of skill in the art without departingfrom the scope of the invention, which is defined solely by the claimsappended hereto.

1. An exhaust flange assembly comprising: first and second flanges forrespectively receiving ends of first and second pipes to be joined, saidflanges being securable to each other to join said pipes, said flanges,when abutted against each other, having at least two pairs of opposingholes therethrough; and fastening means positionable through said pairsof opposing holes to secure said flanges to each other, said fasteningmeans comprising, for each pair of said opposing holes: an attachmentportion positionable into a said opposing hole in said first flange,prevented from rotation in that hole, said attachment portion having anabutting portion outside that hole to contact the flange and anengagement portion extending into that hole, at least the engagementportion of the attachment portion having a threaded bore; and a boltpositionable through the opposing hole of the second flange, forscrewing into said threaded bore so as to secure the flanges to eachother; wherein the engagement portion partially extends into said secondflange.
 2. An exhaust flange assembly as in claim 1, wherein said boredoes not extend fully through said attachment portion.
 3. An exhaustflange assembly as in claim 1, wherein said attachment portion beingprevented from rotation in said opposing hole in said first flange is byat least a portion of said engagement portion having a non-circularcross-section corresponding to a non-circular portion of said opposinghole in said first flange.
 4. An exhaust flange assembly as in claim 3,wherein said non-circular cross-section is provided by said engagementportion having at least one flat.
 5. An exhaust flange assembly as inclaim 3, wherein said non-circular cross-section is provided by saidengagement portion having an eccentric cross-section.
 6. An exhaustflange assembly as in claim 1, wherein said attachment portion beingprevented from rotation in said opposing hole in said first flange is bysaid engagement portion having splines or knurling.
 7. An exhaust flangeassembly as in claim 1, wherein at least one said flange is of sinteredpowder metal.
 8. An exhaust flange assembly as in claim 7, wherein saidbore does not extend fully through said attachment portion.
 9. Anexhaust flange assembly as in claim 7, wherein said sintered powdermetal is a mixture of carbon or stainless steel and hexagonal BoronNitride (hBN).
 10. An exhaust flange assembly as in claim 1, wherein oneof said flanges is on the exhaust manifold of an engine.
 11. An exhaustflange assembly as in claim 1, wherein the engagement portion supports agasket inserted between the two flanges.
 12. An exhaust flange assemblyas in claim 1, further comprising a shield covering at least one of thefirst and second flange portions.
 13. An exhaust flange assembly as inclaim 12, wherein the shield is bonded to the first or second flangeportion.
 14. An exhaust flange assembly as in claim 13, wherein theshield is integral with the first or second flange portion.
 15. Anexhaust flange assembly as in claim 13, wherein the shield is integralwith the attachment portion.